Game of Thrones actress Maisie Williams was almost unrecognizable at the March 27 launch of her show's exhibition in New York City, where she showed off long, brunette curls -- a stark change from the super-short boy-cut she sports as Arya Stark on the HBO series. But a source tells Us Weekly that the look was temporary; Williams uses extensions whenever she has a big event or party to attend.

"She [cut her hair] for the show," the insider says. "She just committed. She's a girl, so she'd love to have her long hair back, but it's her job, so she sucked it up."

Williams, whose character on Game of Thrones is on the run and in disguise as a boy, spoke about the decision to cut her hair in a behind-the-scenes video for HBO during the show's second season. (The third season premieres Sunday, March 31.)

"They asked me if I wanted to get my hair cut, and my first reaction was 'No way.' Then I was thinking about it, and people on the internet had said, 'Oh, I don't think she'll get her hair cut. She's too young. It's a big decision to make,'" she explains. "I just sort of wanted to prove them wrong."

And there are some perks to the super-short 'do. "It's way better than last season with all the pins and grips -- that wig was really itchy, too," she says. "I'm pretty lucky, because [for] some people, it takes 40 minutes just to do a wig."